I think you are in the ball park but if it is listed at $9000 you can probably work them down to $7750 to $8250..
There are 3 approaches that I use to buy cars.
1.) Upfront approach: Ask the person what is the minimum they will take for the car. Then knock a bit more off. So if this person says $8500. Then offer them $8000.
2.) Low ball: Check over the car and find any imperfections. Pick the car apart.
Go with cash if possible. $7500 and start there with negotiations.
3.) Budget Approach: Tell the person that you have $10000 to get the car transfered and certified and run it until then end of the year. If the car needs any work then you would like to have a bit of a cushion and money to repair it or maintain it. Start at $7900.